CRD food for thought

nursecosmo · **Posted:** Fri Jul 10, 2009 5:18 pm

fastRob wrote:

1. Catalyst is the law right or wrong. No change in fuel mileage observed.
2. My lift pump makes changing filters easier and if I need more fuel to the injector pump, it will be on tap.
3. Added a tranny cooling radiator with thermal bypass and eliminated the electric fan but do cool down after hot runs. Also did suncoast, tranny pump and shift kit.
4. My biggest performance improvement was cleaning the MAP sensor, the ehm means it does not get dirty again.

5. Still thinking of getting a tune mod and maybe turbo mod with exhaust to my 3" catback $$$$$.

EHM is also against the law. Right or wrong.

gmctd · **Posted:** Fri Jul 10, 2009 7:14 pm

FYI, look at my pics CRD TECH - all three eggs-amples shown - KJ - Suncoast Hemi - Hemi - note the difference in vane angle on the KJ and the two Hemi-vertors: straight on the KJ, curved in the direction of rotation on the Hemi - that vane angle determines the hydraulic hookup which determines the stall speed - the stator is merely the torque-conversion feature, usually about 2.1:1 from dead stop - since the Hemi stall is lower than the KJ, the rpm disparity between non-lockup and lockup will be much lower than in the KJ, meaning the TCC disk will be under reduced duress as the TCC locks and unlocks - that was the area of failure in the pre-11\05 KJ-vertor, resulted from the wide rpm drop and greater torque of the Diesel

Fe, think about how much coffee you can scoop up with a butter knife vs how much with a table-spoon

Typically, a hi-stall convertor for smaller engines also gets a smaller clutch with less apply surface area - lo-stall for powerful engines gets greater vane angle and a larger clutch with greater apply surface area, required to transfer the increased torque

KJ = ~2250 stall

Hemi = ~1850 stall

Compare those with the vane angle on the Cummins TC for the 68RFE, the Godzilla version of the 545RFE - iirc, I posted those pics also

flash7210 · **Posted:** Fri Jul 10, 2009 9:08 pm

Dude!
You gotta post a part # for that Hemi TC.
I have searched every internet parts site and cant find one.
And the dealer cant/wont look up parts without a VIN.

warp2diesel · **Posted:** Fri Jul 10, 2009 10:14 pm

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=30576

danoid · **Posted:** Fri Jul 10, 2009 10:58 pm

OEM's measure torque converters in K factor. I don't have my cheat sheet in front of me but it's something like square root of rpm divided by output torque.

A little torque converter refresher.

A torque converter is essentially a pump that outputs torque instead of fluid, the fluid is recirculated.

A torque converter outputs the same torque at the same input rpm regardless of how that rpm is provided, electric motor, CRD, Hemi, or hamster wheel. It does require input torque to provide that input rpm, that is why higher torque engines accelerate faster than putt putts - they are able to make that input rpm easier easier, or by providing even more torque, move to a higher rpm (more torque output from the converter to the transmission).

A torque converter will have different stall speeds with different engines. The CRD makes more torque at 2200 rpm than a Hemi. Therefore a CRD will have a higher stall speed with the same converter than a Hemi.

However, the Hemi torque converter is a lower K factor than the CRD converter. Why? In a dynamic launch, a turbo diesel rarely generates full boost. An engine accelerating from idle is pulling air out of the intake faster than the turbo can add more in to raise intake pressure (turbo lag). Therefore a higher K factor / stall or 'looser' converter was speced to assist launch. Also a lower K factor / 'tighter' converter will generate more output torque when the vehicle is stopped, which in smaller vehicles like the KJ leads to high brake efforts to stay at a stop light, more fuel being used to maintain idle (lower City EPA sticker) and 'garage shift' issues (Drive to Neutral really clunks). Someone with a Suncoast can probably back me up on this.

There are two other factors to consider about putting a Hemi torque converter in a CRD. THe lockup clutch and the torsion damper. The lockup clutch on most Hemi converters nowadays are grooved to enhance cooling during partial lock. The CRD clutch material was not because there isn't a lot of partial lock used in that application. This could lead to odd lockup feel because the calibration is wrong. Second, the damper is set up for an 8 cylinder which has less torsional vibration than our tractor motors. The spring constant won't be what we really need for this application and it could bottom out causing some significant vibration and possible durability issues.

Just my two cents...

DOC4444 · **Posted:** Fri Jul 10, 2009 11:47 pm

The best solution may end up being the "Euro" TC that GDE is attempting to arrange availability for in the US. This is what is fitted in several DCJ european vehicles that are now being produced with the "new" version of our motor. (It's a 2.8 litre 4 cylinder TD from VMM, but virtually all the parts are new and it makes a LOT more power.)

GDE claims that "our" TC is maxed out at about 250 lb/ft. The "Euro" one is supposed to be good for at least 400 lb/ft. It should address the issues that danoid astutely pointed out because it's developed for a same displacement inline 4 cyl TD.

DOC

DarbyWalters · **Posted:** Fri Jul 10, 2009 11:54 pm

...and that is the TC I have been waiting for in my "Sig". I just hope the wait isn't too long!

danoid · **Posted:** Sat Jul 11, 2009 12:16 am

danoid wrote:

Working on it. Not ready to announce.

gmctd · **Posted:** Sat Jul 11, 2009 12:29 am

A torque convertor outputs torque only when the turbine and transmission input shaft rpm is lower than the drive impeller rpm - most street vehicle torque conversion is in the 2.1:1 - 2.4:1 ratio at dead stop - doesn't matter if it is a 2.4L in a lite chassis or 5.7L in a heavier chassis or 7.4L in heaviest chassis, that torque reduces as turbine shaft rpm approaches impeller rpm, until the unit is just a 1:1 hydraulic coupling - the angle of the impeller and turbine vanes determines the amount of hydraulic coupling, or hookup, from dead stop up thru TCC lockup - the greater the input power, the greater the slip, or stall, within each spec'ed vane angle

Fe, you can put a 10"TC with mild vane angle on a 2.4L engine and get a stall of 2800rpm - put the same 10" TC on a 5.7L engine and get a stall over 5000rpm, depending on the output power of the engine - that has been done in drag-racing since it was determined that properly set-up automatics make the quickest times - go to TCI\equiv for a hi-stall TC for your 5.7L engine and they will sell you the 10" TC originally equipped on a Chevrolet Vega 2.4L 4cyl - and there are smaller versions, down to 8", for even higher stall

The TC and clutch in the KJ-vertor is identical to the TC and clutch in the '03-'04-'05 545-equipped GC 4.7L - that is why it failed with the more powerful KJ CRD - however, I seriously doubt that it is same as the one in the Hemi TC - and that is my only concern with the conversion - the TC clutch for the larger 5.7L Hemi should be stouter than the 4.7L, as the TC vanes are more agressive for better transfer of the increased power output - falls to reason that the TC clutch would be, also, imo

Since the '05-later 5.7L GC's got the NAG transmissions, only the Euro KJ\equiv will continue to get the 545RFE and TCC - it was my understanding that the Hemi TCC is better than 400ftlb and was to be the Euro unit

gmctd · **Posted:** Sun Jul 12, 2009 12:04 am

Understand, Danoid: I'm not being deliberately contradictive - I just posted similar information to yours from a different perspective - I'd really like to get to the bottom of this, as the Suncoast convertor is the Hemi version, just race-hardened - that would imply that my KJ is running the Hemi clutch without problem, but then again, mine never shuddered with the oem TCC - some that shuddered with the oem TCC continue to shudder with the Suncoast TCC - some that shuddered with the oem TCC do not shudder with the Suncoast TCC - this would seem to indicate that the TCC is not the problem, or at least, not entirely causative - what say you?

geordi · **Posted:** Sun Jul 12, 2009 1:31 am

I'm going to jump into this discussion with a third perspective - My KJ only shuddered a couple times, nothing that I could repeatedly trigger. I had the guys working on the engine pull the TC and asked them to have their converter shop build it up and replace any plastic they found inside it.

Instead, they sent over a new TC that they had built, and said that it had no plastic in it at all, and was built to take anything my engine could dish. We shall see, but for $100 for the whole thing... I'm willing to take that shot! I haven't asked yet if this is the hemi TC, so that is still TBD.

gmctd · **Posted:** Sun Jul 12, 2009 1:46 am

Post a pic - that should tell the tale..................

nursecosmo · **Posted:** Sun Jul 12, 2009 3:56 am

A funny thing that happened when My Jeep sat for three weeks while I was overseas, is that When I returned, it will no longer shudder. I can't make it shudder in any situation, even when towing my boat which weighs ~500 Kg with the trailer. It had been getting harder and harder to make shudder ever since I added the DR Tranny additive. My thought is that sitting for so long allowed the friction modifier to soak into the clutch material.

Squeeto · **Posted:** Sun Jul 12, 2009 3:35 pm

From GreenDieselEngineering post #14 on this thread-

Quote:

The Bosch CP3 fuel pump on the KJ CRD includes a positive displacement pump on it called a ZP18 lift pump. Most other manufacturers do not use the ZP18 and require an in-tank lift pump. Newer designed Bosch pumps CP3+, CP4 and CP4+ all require an in-tank lift pump. The KJ was designed before these were available on the market. It is not a perfect design and that is why Bosch has since changed their products, it is easier to push instead of pull when it comes to fuel systems.

GDE is saying that we already have a lift pump, it is not perfect and an in-tank pump would be better.
So really no one is saying we don't need a lift pump only that we don't need an extra one.

For those of us with issues, how about installing an in-tank pump and circumventing the ZP18 (which may add more leak points) in the diesel line?

gmctd · **Posted:** Sun Jul 12, 2009 4:23 pm

Even for those without issues (a veritable pshychiatrist's dead pool) the lift pump is part of the CP3, driven by the pump shaft, so there are no fuel lines to worrry about - fyi, the Cummins and the Dmax CP3 pumps both have the medium-pressure gear-type lift pump and the COP regulator valve - Dmax tried that no aux lift pump bs, so the owners all installed aftermarket electric lift pumps, usually from Kennedy Diesel (we gots a few of'em, here) - Dodge installed a lift pump up on the fuel manager cannister, only to have them fail right and left in '03-'04-'05, at which point ('05) DCJ spec'ed the intank lift pump which we all now know and love...................

Squeeto · **Posted:** Mon Jul 13, 2009 12:36 am

Quote:

the lift pump is part of the CP3, driven by the pump shaft

The end of the line. Seems like the worst place for a lift pump.

gmctd · **Posted:** Mon Jul 13, 2009 12:54 am

Not if you want it to draw 26"HG vacuum and reliably pump 180psi...................

Squeeto · **Posted:** Mon Jul 13, 2009 1:07 am

GDE stated that

Quote:

Most other manufacturers do not use the ZP18 and require an in-tank lift pump.

Are you saying that a lift pump is still needed at the shaft of the CP3 if there exists an in-tank lift pump?
Restated- to draw 26"HG vacuum and reliably pump 180psi, the newer designed CP3+, CP4 and CP4+ have a lift pump at the shaft and an in-tank lift pump?

gmctd · **Posted:** Mon Jul 13, 2009 1:35 am

Read thru my CP3 IP operational thread in CRD TECH - the pic there is the pump used in the KJ's, the Dodges, and the Dmax'es - note the cutaway of the lift pump on the rear housing - dunno what the '09's are using, but to get the 80psi in the KJ and the 180psi in the Cummins and Dmax you'll need a more powerful lift pump in the tank than what we're currently using - it's good for only 9.5psi - others barely make 4.5psi

FYI: forget about all the other CP3xxx information - it doesn't concern our KJ's, and we cannot do anythng about it either way anyway no way - what we're concerned with is the CP3 that the KJ CRD rolled off the production line with, and that, empirically, the fuel supply is overall more reliable with an auxiliary lift pump pushing fuel from the tank - which is what GDE is hinting at, and very likely why DCJ provided lift pump control-logic in the ECM, lift pump relay and lift pump wiring back to the fuel tank for an auxiliary electric lift pump very near, at, or very in that tank - try it, you'll like it.................

NJCRD · **Posted:** Mon Jul 13, 2009 10:27 am

So Danoid,
I checked the part number on the F37 recall. They check out, new converter and the new pump per your part numbers. So now as far as the stalling issue that I have, I'm guessing the converter may just be screwed.

CRD food for thought

Who is online